1. Field of the Invention
This invention relates to aqueous gels prepared from nonionic surfactants in mineral oil. These gels are particularly useful in the formation of topically applied cosmetic and pharmaceutical compositions.
2. Description of Earlier Work and Discoveries
U.S. Pat. No. 3,740,421 relates to polyoxyethylene-polyoxypropylene aqueous gels. Polyoxyethylene-polyoxypropylene block copolymers form gels within certain specified ranges of compositions with water. U.S. Pat. No. 3,639,574 relates to hydrogen peroxide gels prepared employing certain polyoxyethylene-polyoxypropylene block copolymers as gelling agents. U.S. Pat. No. 3,579,465 relates to polyoxyethylene-polyoxypropylene adducts of ethylene diamine which, within specified limits form aqueous gels. These gels are prepared by dissolving the block copolymer in water at a temperature between 1.degree. C. and 10.degree. C. and thereafter warming to about 30.degree. C. to form the gel.
Among the problems of these gel compositions is that they liquify at temperatures below about 30.degree. C. Therefore, they cannot be stored as gels in a refrigerator or freezer or in a cold room, below normal room temperature.
U.S. Pat. No. 2,828,345 discloses emulsifying mineral oil in water with a series of butylene oxide-ethylene oxide polymers having a molecular weight of the butylene oxide groups of 1100 to 1400 and having oxyethylene weight percents ranging from 40 to 80. U.S. Pat. No. 4,040,857 discloses compositions exemplified by thixotropic emulsions employing as emulsifiers copolymers of butylene oxide, propylene oxide and ethylene oxide. All three components are essential in this patent.
Copending U.S. patent application, Ser. No. 287,203, filed July 27, 1981, discloses a polyoxybutylene-polyoxyethylene aqueous gel. There is no mention therein of mineral oil. In the prior art the preparation of stable homogeneous gel systems of mineral oil and water generally requires complex processes and apparatuses such as homogenizers.